Tubing protectors



July 31, 1962 R. c. DAVIS 7,025

TUBING PROTECTORS Filed Jan. 50, 1957 2 Sheets-Sheet 1 n m m Roy (J. Davis INVENTOR.

ifMMjiw M E A TTORNZYS July 31, 1962 R. c. DAVIS TUBING PROTECTORS 2 Sheets-Sheet 2 Filed Jan. 50, 1957 5 6 w iw W a E j m aw m E 2 32:1: 7 V/////// n E a a 'f'ifllllifll'lillllllll I Roy 6. Davis INVENTOR ATTORNEYS tion.

3,047,025 TUBING PROTECTORS Roy C. Davis, Dallas, Tex., assignor to The Guiberson g This invention is concerned with protection means for the tubing or'other pipe extending into a well and is particularly concerned with protector sleeves made of elastic material which are arranged to be stretched about a section of tubing or other Well pipe wherein the adjoining protector sleeves have overlapping and/or inten-locking ends which form a sealed and interlocked joint between adjoining protector sleeves.

Many oil or gas wells have two or more productiv formations at different levels. of producing dual formations is to set a casing packer between the formations and extend a tubing through the packer with a perforated tailpipe at the lower end. The tubing has sealing elements thereabout which seal within the bore of the packer. The production fluid from the lower zone of production is produced through the tubing string and the production fluid from the upper zone is produced through the annulus between the tubing and the casing.

In another form of dual completion a second casing The conventional manner.

United States Patent packer is set above the upper zone and a cross-over device is mounted in the tubing string above the upper packer to direct the 7 production from the lower zone through the casing annulus and the production from the upper zone through the tubing.

In either form of dual completion a section of the well tubing extends through a productive formation and is exposed to the production fluid as it enters the casing through perforations in the wall of the casing.

I The production fluid is usually under pressure from the formation and passes through the restricted perforations in the casing at high velocity and. in jetted streams; Such production fluid usually has a high content of sandand other abrasive material so that it impinges against the tubing, cuts and erodes -the surface thereof, and soon weakens it m the extent that it is ruptured and must be replaced.

It is, therefore, desirable to protect the tubing. from the eroding action of the fluid frornthe productive formation through which tubing passes.

Several'means have been employed in the past in an I method also requires expensive shop equipment and greatly increases the cost of application.

Another such attempted protection means has been the wrapping of the tubing section with rubber or rubber-like compound and curing the rubber about the tubing in an open steam bath. Such method is unsatisfactory because of the ditficulty of securing a satisfactory bond and the poor quality of the rubber so cured. It is also expensive in that it requires shop facilities for its applica- In some instances the tubing section has been coated found that it is readily destroyed by the sand-laden well fluids.

I Still another protection means attempted in the past Ice 2 4 has been the placing of a plurality of abutting rubber sleeves about the tubing- Such practice has not been entirely satisfactory because of the fact that in running the tubing into the well the rubber sleeves are often separated by mechanical drag against the casing, leaving the tubing exposed therebetween. Furthermore, the jetted production fluid often enters the casing with such velocity that it will penetrate the joints between the sleeves and force the sleeves apart, exposing the tubing to the abrasive action of the fluid.

It is a primary object of this invention to provide tubing protectors which are so placed on the tubing that they will completely encase and cover the tubing in the area desired and will maintain complete coverage and protection of the tubing while the tubing is being run into the well and thereafter while the well is on production.

Another important object of this invention is to provide tubing protector sleeves having overlapping and interlocking ends which prevent the protector sleeves from spreading apart by mechanical drag while being run into the well or by reason of jet action of the well fluid from a producing zone.

A still further object of this invention is to provide tubing protector sleeves of elastic material having overlapping and interlocking end portions which are firmly en gaged and sealed when the protector sleeves are stretched about the tubing and are retained in such position while being run into the well and after being run into the well. Still another object of this invention is to provide a rubber pipe protector sleeve which may be molded under high compression, assuring a consistently dense and uniform finished product of high quality capable of resisting the "erosive and/or corrosive action of well fluids.

A further object of this invention is to provide protector sleeves which can be easily and inexpensively applied to a tubing section in the field, in such numbers as may be desired, to cover and protect the tubing section with a rubber sheath.

A general object of this invention is to provide a tubing protector sleeve construction which permits a plurality of such sleeves to beplaced on a section of tubing in overlapping, sealed and interlocking relationship so as to positively encase and protect the tubing against abrasive action of well fluidfrom a producing formation.

Other and further objects of my invention will become apparent upon reading the detailed specification hereinafter following and by referring to the drawings annexed hereto.

Preferred embodiments of the invention are shown in the attached drawings wherein, 7

FIGURE I is a quarter sectional, elevational view of a tubing protector sleeve made in accordance with ,the preferred form of my invention.

FIGURE II is a cross-sectional, elevational view of a portion of a cased well here having two zones of production, and showing a section of tubing extending through a packer set in the casing, and showing a sectionalized elevational view of two overlapping and interlocking tubing protector sleeves stretched about the tubing adjacent view of two overlapping and interlocked protector sleeves disposed about a section of tubing adjacent a productive formation in a well, and showing the jet action of the production fluid against the protector sleeves as the fluid passes through the perforations. in the casing.

FIGURE IV is a cross-sectional, plan view taken on the line IV-IV of FIGURE In.

FIGURE V is an elevational view, partially incrosssection, showing a dual completion installation in a well wherein a packer is set between the two productive formations, and a packer is set above the uppermost productive formation, with a cross-over device incorporated in the tubing string above the uppermost packer, and showing modified forms of overlapping and interfitting protector'sleeves on the tubing adjacent the upper productive formation.

FIGURE V1 is a perspective view of two of the modified forms of protector sleeves, showing the interfitting and overlapping relationship therebetween.

FIGURE VII is a cross-sectional, elevational view of a plurality of modified protector sleeves stretched about a section of tubing adjacent a productive formation, illustrating the overlapping relationship between the protector sleeves and the impingement action of production fluid against the protectors as the well fluid passes through the perforations in the casing.

Although the protector sleeves are illustrated and described herein as being employed to protect a well tubing, it will be understood that they could be employed to protect any pipe or rod extending into a well. The drawings and descriptions herein are merely illustrative of typical uses and applications of the invention and are not to be construed in a limiting sense.

Numeral references are employed to designate the various parts of devices shown in the drawings and like numerals indicate like parts throughout the various figures of the drawings.

FIGURE I illustrates in a quarter sectional, elevational view a preferred form of construction of an individual protector sleeve, incorporating the improvements forming parts of this invention.

In such form the protector sleeve is designated generally by the numeral 10. The protector sleeve is preferably .made of elastic and resilient material, such as natural or synthetic rubber, and such material is elastically retractable so that it may be stretched about a pipe or other cylindrical member of greater outside diameter than the internal diameter of the bore of the sleeve to thereby tightly grip the pipe by elastic force.

The tubing protector sleeve 10, shown in FIGURE I, consists of a main body portion of resilient material, designated by the numeral 11, which body is preferably cylindrical in shape. The protector sleeve is preferably molded in one piece by compression molding and includes a neck portion 12 at one end which is smaller in outside diameter than the main body 11 and having a lesser wall thickness than the main body 11. The lower end of the protector sleeve is terminated by an outer annular rib 16 which is larger in outside diameter than the neck portion 12, but is slightly lesser in outside diameter than the main body portion 11. There is thus formed between the main body portion 11 and the rib 13 an outer annular channel 14.

A main bore 15 is provided in the protector sleeve 10, which bore is preferably smaller in diameter than the pipe or other cylindrical member about which the protector sleeve is intended to be stretched.

An annular internal recess 16 is formed in the upper end of the body 11, which recess '16 is of complementary shape to the rib 13 so that when the rib 13 on an adjoining sleeve 10 is inserted in the recess 16 there is an interfitting and sealed relationship therebetween.

The upper end of the sleeve 10 is terminated by an annular internal rib 17 which is complementary in shape to the external channel 14 at the other end of the sleeve, so that the internal annular rib '17 is arranged to interfit and seal within an annular channel 14 on an adjacent and joined sleeve 10.

produced through the annular space between the tubing and the casing.

The tubing string 20, which includes a number of joints of pipe extending from the earths surface, is joined to a section of tubing 21 by means of a coupling 22. The

section of tubing 21 extends through a conventional casing packer 23 which is set to seal against the wall of the casing 26, the packer 23 being anchored to the casing by conventional slips 24 and 25. A perforated tailpipe 28 is attached to the lower end of the tubing section 21 and production fluid from the productive formation A enters the casing 26 through the perforations 29, in the wall of the casing 26, passes through the perforated tailpipe 28 and upwardly through the tubing string to the surface.

Production fluid from the upper productive formation B enters the casing 26 through the perforations 30 in the casing and rises to the surface through the annular space between the casing and the tubing string. 7

FIGURE 11 is merely illustrative, and in actual practice there may be a number of joints of tubing between the packer 23 and the tailpipe 28. Likewise there may be a number of joints of tubing between the tubing sec- I tion 21 and the packer 23.

In any event the tubing section 21 passes through, and is adjacent to, the productive formation B.

There is shown, by way of illustration in FIGS. II and III, two interlocked tubing protector sleeves 10 mounted on the tubing section 21, adjacent the formation B, to protect the tubing against the abrasive, erosive, corrosive and jetting action of production fluid passing through the perforations 30 in the casing wall.

In actual practice there may be any number of overlapping and interlocking protector sleeves 10 arranged about the tubing section 21, there being sufficient number to. completely cover that portion of the tubing which would be exposed to the jetting action of fluids produced from the productive formation through which the tubing passes.

The tubing protector sleeves 10 are placed on the tubing section to be protected while thetubing string is being made up at the earths surface, and such protector equipped tubing section is incorporated in the tubing string at the correct place as the tubing string is run into the well.

The bore 15 of the protector sleeve 10 is preferably smaller in internal diameter thanthe outer diameter of the tubing section on which it is placed. For example, a tubing protector to be placed on a 2% -inch O.D. tubing section would have an interior bore diameter of l%-inch. Therefore, the protector sleeve must be stretched over the tubing section so that it has a tight, elastic, impinging engagement with the tubing section after it is expanded and stretched thereon. 7

As the individual protector sleeves 10 are stretched and forced onto the section of tubing 21, the complementary, overlapping and interlocking ends of adjoining protector sleeves are forced together and interfitted in the manner shown in FIGURES II and III. As so disposed the rib 13 on one protector sleeve is forced into the recess 16 on the adjoining protector sleeve as the internal rib 17 is forced into the external recess 14. The interlocking relationship between adjoining protector sleeves 10 is indicated by the numeral 32.

As illustrated in FIGURES II and III, and indicated by the numeral 33, when the elastic protector sleeve 10 is stretched and forced upon the tubing section 21, the rib 17 is caused to curl or move inwardly against the tubing by reason of the tendency of the sleeve 10 to shorten as it is expanded radially. Therefore, in order to insert the rib 13 in the groove 16 on adjoining sleeves it is necessary to expand and stretch the rib 17, setting up tight, gripping elastic tension between the interengaged ends of the protector sleeves. Therefore, the ends of adjoining protector sleeves 10 are not only firmly interlocked but the joints therebetween are sealed together by impinging contact to thereby positively prevent the protector sleeves from coming apart, and preventing jetted fluid from the productive formation from penetrating the joints.

In FIGURES III and IV there is illustrated and indicated by the numeral 31 the jetting action of production fluid passing through the casing perforations 30 from the productive formation B, adjacent the overlapped and interlocked protector sleeves 10. It will be seen that in the absence of such protector sleeves about the tubing the jetted fluid would strike the tubing and cut, erode and sever or rupture the tubing section adjacent such formation. The resilient protector sleeves absorb the impact of the formation fluid and the overlapping, interlocking and sealed joinder between the protector sleeves prevents the fluid from penetrating the joints between the protectors, prevents the protector sleeves from being pushed apart by contact with the, casing as they are being lowered into the well and also prevents the jetting action of the fluid from separatingthe protectors after they have been positioned in the well adjacent a zone of production.

Thus it will be seen that the protector sleeves entirely encase and protect the tubing in a resilient protective sheath and they are so interlocked and interengaged that they will not separate and expose the tubing to abrasive action of the well fluid, and no fluid can penetrate the joints therebetween.

In FIGURE V there is shown another form of dual completion of awell wherein the fluid produced from the lower zone of production C is crossed over to be produced through the annular space between the casing and the tubing and the fluid produced from the upper zone of production D is produced through the tubing string.

In such installation it will be noted that a casing packer 49 is set above the upper zone D, such packer being anchored to the casing 45 by slips 50 and 51.

It is necessary to pass the tubing protector sleeves through the upper packer 49 in running the tubing into the well to position them adjacent the upper zone D, after the packer 49 has been set. Therefore, since the axial passage through the packer 49 is of uniform and limited diameter, it is necessary to employ protector sleeves having an outside diameter which will pass through said packer.

The alternate form of protector sleeve 36, two of which are shown in FIGURE VI, has a lesser wall thickness than the preferred form of protector sleeve 10, and when disposed on the tubing has an outside diameter small enough to pass through the bore of the conventional packer 49. Such alternate form of protector sleeve has particular application in dual completion installations such as shown in FIGURE V, where it is necessary to pass a section of tubing equipped with protector sleeves through a casing packer.

The alternate form of protector sleeve 36 is preferably cylindrical in shape and has -a main body portion 37 with a main bore 38 therethrough. It is made of resilient elastic material and is preferably molded in'one piece by compression molding.

An extension 39, of reduced diameter, is provided on one end of the sleeve 36 and an annular internal recess 40 is formed on the other end of the sleeve. The extension 39 and recess 40 on adjoining sleeves 36 are complementary and are arranged to interfit in overlapping relationship, as illustrated in FIGURES VI and VII.

In making a dual completion installation as shown in FIGURE V the packers 49 and 53 are first set and anchored to the casing 45, by meansof the slips 50--51 and 54-55, respectively, at the proper levels above and below the upper formation D. The tubing string 44 is made up at the earths surface as it is run into the well and includes a conventional cross-over device 46, which is attached to the tubing string by means of a coupling 47. A section of tubing 48, which may or may not form a part of the cross-over device 46 extends through the packer 49. A flow separating nipple 52 is attached to the section of tubing 48, and another section of tubing 56 is attached to the other end of the flow separating nipple 52. The tubing section 56 extends through the packer 53. A perforated tailpipe 57 is attached to the section of tubing 56 below the packer 53.

Production fluid from the lower formation C enters the tubing through the tailpipe 57. The tubing section 56 ex:

tends through the productive formation D,: and has stretched thereon a plurality of protector sleeves 36 with overlapping and sealed end sections. In'the absence of the protector sleevesjG, the tubing section 56 would be exposed to the eroding force of the production fluid entering the casing through the casing perforations 59. However, the tubing is protected against the jetting action of the well fluid, indicated at 60, by the protector sleeves.

In installing -a plurality of protector sleeves 36 on the tubing section 56 (or any other pipe section), the same are stretched and forced thereon at the earths surface and the tubing section 56 is' incorporated in the tubing string 44 at the proper position as it is made upland run into the well.

The internal bore 38 of the protector sleeve 36 is smaller in diameter than the outside diameter of the.

tubing section over which it is stretched, as explained in connection with the preferred form 10, so that it is in tight, elastic engagement with the tubing section when stretched thereon. When the protector sleeve 36 is stretched onto the tubing section 56 the thin end portion 61 curls inwardly against the-tubing, as shown in FIG- URE VII, so that it is necessary to stretch and expand the end 61 to force the extension 39 on an adjoining protector into the recess 40. Therefore, there is a tight, elastically sealed engagement between the end 61 and the extension 39 of adjoining protector sleeves. -The overlapped ends are so tightly engaged and frictionally joined that they will not come apart by reason of mechanical drag against the casing while being run into the well or by reason of the jet action of the production fluid after being positioned in the well adjacent a productive formation.

Of course, as many protector sleeves 36 may be placed in overlapping and interlocking relationship on a section of tubing as may be required to completely traverse a productive formation and protect it from abrasive and eroding action of the product-ion fluid.

It will be noted that the outside diameter of the protector sleeves 36, when disposed on the tubing, are such that they will pass through the internal bore of the packer 49 when run into the well.

In the dual completion installation shown in FIGURE V, production fluid from the formation C passes through the perforations 58 in the casing, through tailpipe 57, through the tubing section 56, through passage 62 in flow separating nipple 52, through central passage 63 'in cross over device 46, and outwardly through the lateral port 64 in such cross-over device into the casing annulus and thence to the surface.

Fluid from production zone D enters the casing annulus through the perforations 59 in the casing 45. Such fluid passes through the side ports 65 in the flow separating nipple 52, upwardly through the tubing section 48,

annular passage 66 in cross-over device 46, through central passage 67 in such cross-over device, and through the tubing string 44 to the surface.

In both forms of the protector sleeve, illustrated and described herein, a plurality of such sleeves may be disposed about a section of tubing or other pipe in interlocking and overlapping relationship in such manner that they give positive coverage and protection of the tubing adjacent a productive formation in the well and the protector sleeves will not come apart at the joints while being run into the well and after being run into the well. They, therefore, protect the tubing against wear and erosion from the well fluid jetted through perforations in the casing from a surrounding productive formation. They are easily installed in the field and are compression molded under controlled conditions assuring uniform good quality to give effective and long lasting protection.

It will be apparent to those skilled in the art that other and furtherforms of my invention may be devised wit-h- 7. out departing from the spirit and scope of the appended claims. A

I claim:

1. A protected device comprising, a well pipe; a plurality of elastic sleeves radially stretched about the well pipe and held in such stretched condition thereby; each sleeve when relaxed having a bore of lesser diameter than the outer diameter of the well pipe on which it is mounted; a portion of reduced outer diameter on one end of each sleeve; an internal annular recess provided inside the other end of each sleeve, providing a wall portion therea-bout of reduced thickness which curls inwardly toward the pipe when the sleeve is stretched on the pipe; the said sleeves being stretched on the well pipe in abutting relationship with the reduced end portion on one sleeve forced into the recess of an adjoining sleeve to elastically stretch the inwardly curled reduced thickness wall portion thereover, the said recess and reduced end portion being complementary in shape and length so that the reduced end portion fills the recess and the overlapped ends formed thereby are in elastically gripped and sealed relationship.

2. A protected device comprising, a well pipe; a plurality of elastic sleeves radially stretched about the well pipe and held in such stretched condition thereby; each sleeve when relaxed having a bore of lesser diameter than the outer diameter of theiwell pipe on which it is mounted; a portion of reduced outer diameter on one end of each sleeve; an external annular rib arranged about the reduced end portion; a recess having therein an internal annular groove provided in the other end of the sleeve; the said sleeves being disposed on the well pipe 8 in abutting relationship with the reduced end portion inserted in the end of an adjoining sleeve so that the rib thereon is disposed in the internal annular groove in such adjoining sleeve; the said recess and reduced end portion being complementary in shape and length so that the reduced end portion fills the recess with the rib disposed in the groove.

3. In a protected device, a well pipe; a plurality of elastic sleeves radially stretched about the well pipe and held in such stretched condition thereby; each sleeve when relaxed having a bore of lesser diameter than the outer diameter of the well pipe on which it is used, the said sleeves being in abutting relationship and having overlapping end portions; one end portion being forced within the other end portion to fill and elastically expand same to thereby provide elastically gripped and sealed overlapping ends.

References Cited in the file of this patent UNITED STATES PATENTS Collett Mar. 20, 1956 

